The rust-js layer can be slow. But the actual rust code is much faster than the equivalent JS in my experience. My project would not be technically possible with javascript levels of performance
the JS layer is slow, indeed, but it shouldn't be that much slower that it meaningfully impacts frontend apps
A demonstration of that by the creator of Leptos:
That's fair and makes sense. In my case it was just a regular web app where the only reason for it being in Rust was that I like the language.